I haven't been to that side of the fjord in about 25 years, and my Norsk really sucked. But here's what i remember. Along the E6 there are some viking mounds and some ancient grave markers near Råde (i remember they looked like a miniature stonehenge). If you have time to spend in Oslo, go there as well. Rent a car and drive as far around as you can. The larger towns are more architecturally interesting as there you'll find more of the tiny alleys and buildings older than than the US. The western side of the fjord has more of the hilly terrain (and touristy destinations), but everywhere is losing sunlight this time of year. And if you're around on a Saturday night, in Oslo that's when the American Car Club enthusiasts would cruise and hang out (amcar.no). Those streets are never so dangerously narrow as when tooling about in a '70s muscle car, and they're a fun group to hang with. As for shops, i remember further up north the rule was to stay away from anywhere that had wooden trolls out front; that marked a shop that was priced for tourists.

I'll be interested to know if any of this is helpful, or even still valid. But when you get there you'll meet people who'll help you find something. And if the weather keeps you inside, the food will make up for it.

I don't know Fredrikstad, but it's not far from Oslo, you can arrive in one hour, with train. Here's is the train company website: http://www.nsb.no/?lang=en_US

Oslo it's a good place to visit. Some art museums, and some nice parks, for example Frognerparken, a huge park with a lot of sculptures of Gustav Vigeland (dedicated to human body and feelings)http://www.vigeland.museum.no/en/vigeland-park

If you'll stay more days i recommend to visit the west coast ( the city of Bergen and the fiords ). But prepare raincoat and umbrella. ( if you come say something and we can drink a hot coffee :) )

Somebody said that you can rent a car and drive as far as you can. Yes, it's an option, but i don't recommend this. It's winter, and you can very easily find snow and ice on the road. And the norwegian roads are bad !

Prepare winter clothes !! important, the east part is normal to have temperatures between 0º and -15º ( or more ) in winter.Here you can check: http://www.storm.no/vaer/fredrikstad

I saw that you're going to make a seminar. I have the idea to go to the festival, but at this moment I don't know if I can go. I hope !

John K coming to my hometown! This is too good to be true! You have to go see the Old Town for sure.. I could dig up some more sights for your eyes to lay upon. Are you going to have a talk there? From Ingrid, a BIG Ren & Stimpy fan

I'm late to the party here but thought I'd mention that Fredrikstad is Norway's (Northern Europe's?) best preserved fortress town - the area that is now described as the Old Town. It's across the river from the new one (there's a ferry going every half hour or so) and has loads of original houses and the intact fortification walls around it. Oslo, apart from what's mentioned here has a lot of historical museums on the Bygdøy peninsula (Norsk Folkemuseum (old houses over a large area, including a stave church), The viking ship museum, with the world two best preserved original viking longships), the kon-tiki museum for Thor Heyerdahl fans and the Fram museum for Frdtjof Nansen-/Roald Amundsen-fans. Also there is another fortress/old castle on the shoreline in the middle of town, Akershus festning, with a lot of 17th century houses nearby, and there is also the Oslo Old City, with ruins of the original Oslo settlement (church/monastery) from around year 1000AD. If you're into old buildings there should be plenty to fill a day or two.